feat: add CLIP embedding service sidecar for GPU machine

FastAPI service that loads ViT-L-14 model and exposes /embed,
/similarity, and /batch-similarity endpoints. Runs on RTX 3090
with NVIDIA GPU reservation. Includes 9 cosine similarity tests.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
2026-03-07 17:17:42 -06:00
parent b7c729d331
commit 74e12eca60
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"""Test configuration: mock heavy dependencies that aren't needed for unit tests."""
import sys
from unittest.mock import MagicMock
# Mock modules that are not installed in the test environment.
# The tests only exercise pure numpy math, not model inference.
for mod_name in [
"torch",
"open_clip",
"fastapi",
"fastapi.responses",
"pydantic",
"PIL",
"PIL.Image",
"uvicorn",
]:
if mod_name not in sys.modules:
sys.modules[mod_name] = MagicMock()
# Provide a real BaseModel stand-in so Pydantic models can be defined
# (they are referenced at import time in main.py).
import types
pydantic_mock = sys.modules["pydantic"]
class _FakeBaseModel:
def __init_subclass__(cls, **kwargs):
pass
def __init__(self, **kwargs):
for k, v in kwargs.items():
setattr(self, k, v)
pydantic_mock.BaseModel = _FakeBaseModel
# Provide a fake FastAPI and HTTPException so the module loads
fastapi_mock = sys.modules["fastapi"]
class _FakeFastAPI:
def __init__(self, **kwargs):
pass
def get(self, *a, **kw):
def decorator(fn):
return fn
return decorator
def post(self, *a, **kw):
def decorator(fn):
return fn
return decorator
class _FakeHTTPException(Exception):
def __init__(self, status_code=500, detail=""):
self.status_code = status_code
self.detail = detail
fastapi_mock.FastAPI = _FakeFastAPI
fastapi_mock.HTTPException = _FakeHTTPException
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"""Tests for CLIP service math utilities.
These tests exercise the cosine similarity logic using pure numpy --
no GPU, no model loading, no network calls required.
"""
import numpy as np
import pytest
# Import the cosine_similarity function directly from the app module.
# We add the app directory to sys.path so the import works without
# installing the package.
import sys
import os
sys.path.insert(
0, os.path.join(os.path.dirname(__file__), "..", "app")
)
from main import cosine_similarity
class TestCosineSimilarity:
"""Test the cosine_similarity helper function."""
def test_identical_vectors(self):
"""Identical vectors should have cosine similarity of 1.0."""
v = np.array([1.0, 2.0, 3.0, 4.0], dtype=np.float32)
score = cosine_similarity(v, v)
assert score == pytest.approx(1.0, abs=1e-6)
def test_identical_unit_vectors(self):
"""Identical unit vectors should also yield 1.0."""
v = np.array([0.0, 1.0, 0.0], dtype=np.float32)
score = cosine_similarity(v, v)
assert score == pytest.approx(1.0, abs=1e-6)
def test_orthogonal_vectors(self):
"""Orthogonal vectors should have cosine similarity of 0.0."""
a = np.array([1.0, 0.0, 0.0], dtype=np.float32)
b = np.array([0.0, 1.0, 0.0], dtype=np.float32)
score = cosine_similarity(a, b)
assert score == pytest.approx(0.0, abs=1e-6)
def test_opposite_vectors(self):
"""Opposite vectors should have cosine similarity of -1.0."""
a = np.array([1.0, 2.0, 3.0], dtype=np.float32)
b = np.array([-1.0, -2.0, -3.0], dtype=np.float32)
score = cosine_similarity(a, b)
assert score == pytest.approx(-1.0, abs=1e-6)
def test_zero_vector_returns_zero(self):
"""A zero vector should return 0.0 (guarded against division by zero)."""
a = np.array([0.0, 0.0, 0.0], dtype=np.float32)
b = np.array([1.0, 2.0, 3.0], dtype=np.float32)
score = cosine_similarity(a, b)
assert score == pytest.approx(0.0, abs=1e-6)
def test_high_dimensional(self):
"""Test with 768-dimensional vectors (CLIP ViT-L/14 output size)."""
rng = np.random.RandomState(42)
a = rng.randn(768).astype(np.float32)
# Similarity with itself should be 1.0
score = cosine_similarity(a, a)
assert score == pytest.approx(1.0, abs=1e-5)
class TestBatchSimilarity:
"""Test batch similarity logic (matching the endpoint's numpy math)."""
def _batch_similarity(
self, query: np.ndarray, candidates: np.ndarray
) -> tuple[list[float], int, float]:
"""Replicate the batch-similarity endpoint logic."""
query_norm = query / (np.linalg.norm(query) + 1e-10)
candidate_norms = candidates / (
np.linalg.norm(candidates, axis=1, keepdims=True) + 1e-10
)
scores = candidate_norms @ query_norm
scores_list = [float(s) for s in scores]
best_index = int(np.argmax(scores))
best_score = scores_list[best_index]
return scores_list, best_index, best_score
def test_best_match_index(self):
"""The candidate most similar to the query should be identified."""
query = np.array([1.0, 0.0, 0.0], dtype=np.float32)
candidates = np.array(
[
[0.0, 1.0, 0.0], # orthogonal
[0.9, 0.1, 0.0], # close match
[1.0, 0.0, 0.0], # exact match
[0.5, 0.5, 0.0], # partial match
],
dtype=np.float32,
)
scores, best_idx, best_score = self._batch_similarity(query, candidates)
assert best_idx == 2
assert best_score == pytest.approx(1.0, abs=1e-5)
assert len(scores) == 4
# Orthogonal candidate should score ~0
assert scores[0] == pytest.approx(0.0, abs=1e-5)
def test_single_candidate(self):
"""Batch with a single candidate should work correctly."""
query = np.array([1.0, 1.0], dtype=np.float32)
candidates = np.array([[1.0, 1.0]], dtype=np.float32)
scores, best_idx, best_score = self._batch_similarity(query, candidates)
assert best_idx == 0
assert best_score == pytest.approx(1.0, abs=1e-5)
def test_scores_ordering(self):
"""Scores should reflect relative similarity to the query."""
query = np.array([1.0, 0.0], dtype=np.float32)
candidates = np.array(
[
[0.5, 0.866], # ~60 degrees
[0.866, 0.5], # ~30 degrees
[1.0, 0.0], # 0 degrees (exact)
],
dtype=np.float32,
)
scores, best_idx, _ = self._batch_similarity(query, candidates)
# Exact match should be best
assert best_idx == 2
# 30 degrees should score higher than 60 degrees
assert scores[1] > scores[0]